The invention pertains a fire sensor in a polling type fire alarm system in which fire sensors connected to the same line are called in sequence by a fire signal receiver, and the fire sensors thus called transmit the results of their fire sensing operations to the fire signal receiver. More particularly, this aspect of the invention relates to the structure of an address setting section in such a fire sensor.
Recently, a fire alarm system has been proposed in which a microcomputer or the like is employed in a fire signal receiver, and a plurality of fire sensors having individual addresses are connected to a common line extending from the fire signal receiver, wherein the addresses of the fire sensors are sequentially called by the receiver to detect the results of their fire sensing operations. However, a specific method of setting addresses for the fire sensors has not previously been available.
In an example of a conventional address setting structure, an address setting switch is provided in the fire sensor. In assembling the fire sensor, its address is set by operating the switch. When it is required to change the address, the fire sensor must be disassembled, for instance, by removing the cover, etc. This operation is considerably troublesome, taking much time.